Kernel

Commandline Parameters

Talos supports a number of kernel commandline parameters. Some are required for it to operate. Others are optional and useful in certain circumstances.

Several of these are enforced by the Kernel Self Protection Project KSPP.

Required parameters:

• talos.platform: can be one of aws, azure, container, digitalocean, gcp, metal, equinixMetal, or vmware
• init_on_alloc=1: required by KSPP
• slab_nomerge: required by KSPP
• pti=on: required by KSPP

Recommended parameters:

• init_on_free=1: advised by KSPP if minimizing stale data lifetime is important

Available Talos-specific parameters

ip

Initial configuration of the interface, routes, DNS, NTP servers.

Full documentation is available in the Linux kernel docs.

ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>:<dns0-ip>:<dns1-ip>:<ntp0-ip>

Talos will use the configuration supplied via the kernel parameter as the initial network configuration. This parameter is useful in the environments where DHCP doesn’t provide IP addresses or when default DNS and NTP servers should be overridden before loading machine configuration. Partial configuration can be applied as well, e.g. ip=<:::::::<dns0-ip>:<dns1-ip>:<ntp0-ip> sets only the DNS and NTP servers.

IPv6 addresses can be specified by enclosing them in the square brackets, e.g. ip=[2001:db8::a]:[2001:db8::b]:[fe80::1]::controlplane1:eth1::[2001:4860:4860::6464]:[2001:4860:4860::64]:[2001:4860:4806::].

bond

Bond interface configuration.

Full documentation is available in the Dracut kernel docs.

bond=<bondname>:<bondslaves>:<options>:<mtu>

Talos will use the bond= kernel parameter if supplied to set the initial bond configuration. This parameter is useful in environments where the switch ports are suspended if the machine doesn’t setup a LACP bond.

If only the bond name is supplied, the bond will be created with eth0 and eth1 as slaves and bond mode set as balance-rr

All these below configurations are equivalent:

• bond=bond0
• bond=bond0:
• bond=bond0::
• bond=bond0:::
• bond=bond0:eth0,eth1
• bond=bond0:eth0,eth1:balance-rr

An example of a bond configuration with all options specified:

bond=bond1:eth3,eth4:mode=802.3ad,xmit_hash_policy=layer2+3:1450

This will create a bond interface named bond1 with eth3 and eth4 as slaves and set the bond mode to 802.3ad, the transmit hash policy to layer2+3 and bond interface MTU to 1450.

vlan

The interface vlan configuration.

Full documentation is available in the Dracut kernel docs.

Talos will use the vlan= kernel parameter if supplied to set the initial vlan configuration. This parameter is useful in environments where the switch ports are VLAN tagged with no native VLAN.

Only one vlan can be configured at this stage.

An example of a vlan configuration including static ip configuration:

vlan=eth0.100:eth0 ip=172.20.0.2::172.20.0.1:255.255.255.0::eth0.100:::::

This will create a vlan interface named eth0.100 with eth0 as the underlying interface and set the vlan id to 100 with static IP 172.20.0.2/24 and 172.20.0.1 as default gateway.

panic

The amount of time to wait after a panic before a reboot is issued.

Talos will always reboot if it encounters an unrecoverable error. However, when collecting debug information, it may reboot too quickly for humans to read the logs. This option allows the user to delay the reboot to give time to collect debug information from the console screen.

A value of 0 disables automatic rebooting entirely.

talos.config

The URL at which the machine configuration data may be found.

This parameter supports variable substitution inside URL query values for the following case-insensitive placeholders:

• ${uuid} the SMBIOS UUID
• ${serial} the SMBIOS Serial Number
• ${mac} the MAC address of the first network interface attaining link state up
• ${hostname} the hostname of the machine

The following example

http://example.com/metadata?h=${hostname}&m=${mac}&s=${serial}&u=${uuid}

may translate to

http://example.com/metadata?h=myTestHostname&m=52%3A2f%3Afd%3Adf%3Afc%3Ac0&s=0OCZJ19N65&u=40dcbd19-3b10-444e-bfff-aaee44a51fda

For backwards compatibility we insert the system UUID into the query parameter uuid if its value is empty. As in http://example.com/metadata?uuid= => http://example.com/metadata?uuid=40dcbd19-3b10-444e-bfff-aaee44a51fda

talos.platform

The platform name on which Talos will run.

Valid options are:

• aws
• azure
• container
• digitalocean
• gcp
• metal
• equinixMetal
• vmware

talos.board

The board name, if Talos is being used on an ARM64 SBC.

Supported boards are:

• bananapi_m64: Banana Pi M64
• libretech_all_h3_cc_h5: Libre Computer ALL-H3-CC
• rock64: Pine64 Rock64
• rpi_4: Raspberry Pi 4, Model B

talos.hostname

The hostname to be used. The hostname is generally specified in the machine config. However, in some cases, the DHCP server needs to know the hostname before the machine configuration has been acquired.

Unless specifically required, the machine configuration should be used instead.

talos.shutdown

The type of shutdown to use when Talos is told to shutdown.

Valid options are:

• halt
• poweroff

talos.network.interface.ignore

A network interface which should be ignored and not configured by Talos.

Before a configuration is applied (early on each boot), Talos attempts to configure each network interface by DHCP. If there are many network interfaces on the machine which have link but no DHCP server, this can add significant boot delays.

This option may be specified multiple times for multiple network interfaces.

talos.experimental.wipe

Resets the disk before starting up the system.

Valid options are:

• system resets system disk.